[PATCH] perf: ignore exited thread when synthesize thread map

From: Cruz Zhao
Date: Tue Nov 21 2023 - 21:22:07 EST


When synthesize thread map, some threads in thread map may have
already exited, so that __event__synthesize_thread() returns -1
and the synthesis breaks. However, It will not have any effect
if we just ignore the exited thread. So just ignore it and continue.

Signed-off-by: Cruz Zhao <CruzZhao@xxxxxxxxxxxxxxxxx>
---
tools/perf/util/synthetic-events.c | 10 ++++++----
1 file changed, 6 insertions(+), 4 deletions(-)

diff --git a/tools/perf/util/synthetic-events.c b/tools/perf/util/synthetic-events.c
index a0579c7d7b9e..43ad2298a933 100644
--- a/tools/perf/util/synthetic-events.c
+++ b/tools/perf/util/synthetic-events.c
@@ -866,14 +866,16 @@ int perf_event__synthesize_thread_map(struct perf_tool *tool,

err = 0;
for (thread = 0; thread < threads->nr; ++thread) {
+ /*
+ * We may race with exiting thread, so don't stop just because
+ * one thread couldn't be synthesized.
+ */
if (__event__synthesize_thread(comm_event, mmap_event,
fork_event, namespaces_event,
perf_thread_map__pid(threads, thread), 0,
process, tool, machine,
- needs_mmap, mmap_data)) {
- err = -1;
- break;
- }
+ needs_mmap, mmap_data))
+ continue;

/*
* comm.pid is set to thread group id by
--
2.39.3